[rtems-libbsd commit] st-sdmmc: Handle short not cache aligned buffers
Christian Mauderer
christianm at rtems.org
Mon Apr 19 07:04:04 UTC 2021
Module: rtems-libbsd
Branch: master
Commit: 829afafbcbd5503821d59cbdb81bf11860b0864d
Changeset: http://git.rtems.org/rtems-libbsd/commit/?id=829afafbcbd5503821d59cbdb81bf11860b0864d
Author: Christian Mauderer <christian.mauderer at embedded-brains.de>
Date: Tue Apr 13 14:02:39 2021 +0200
st-sdmmc: Handle short not cache aligned buffers
Possible data sources for SD driver:
- mmc_sd_switch():
- length: 64 byte;
- buffer on stack
- mmc_test_bus_width():
- length: 4 or 8 byte
- buffer in program memory or on stack
- mmc_app_send_scr():
- length: 8 byte
- buffer from device ivar structure
- mmc_app_sd_status():
- length: 64 byte
- buffer from device ivar structure
- mmc_send_ext_csd():
- length: MMC_EXTCSD_SIZE = 512
- buffer from device ivar structure
- rtems_bsd_mmcsd_disk_read_write():
- length: depends on read
- buffer from rtems_blkdev buffer -> already aligned
- mmcsd_ioctl_cmd():
- length: depends on call
- buffer malloced, not aligned -> patched in RTEMS
So the problematic buffers are only the ones up to 512 bytes. Copy these data
into a buffer to avoid that problem.
---
rtemsbsd/sys/dev/mmc/st-sdmmc.c | 14 ++++++++++----
1 file changed, 10 insertions(+), 4 deletions(-)
diff --git a/rtemsbsd/sys/dev/mmc/st-sdmmc.c b/rtemsbsd/sys/dev/mmc/st-sdmmc.c
index e50b400..4b20295 100644
--- a/rtemsbsd/sys/dev/mmc/st-sdmmc.c
+++ b/rtemsbsd/sys/dev/mmc/st-sdmmc.c
@@ -117,7 +117,8 @@ __FBSDID("$FreeBSD$");
#define RES_IRQ_SDMMC 2
#define RES_NR 3
-#define DMA_BUF_SIZE CPU_CACHE_LINE_BYTES
+/* Maximum non-aligned buffer is 512 byte from mmc_send_ext_csd() */
+#define DMA_BUF_SIZE 512
#if 0
#define debug_print(sc, lvl, ...) \
@@ -575,14 +576,19 @@ st_sdmmc_cmd_do(struct st_sdmmc_softc *sc, struct mmc_command *cmd)
BSD_ASSERT(xferlen % (1 << blksize) == 0);
- if (xferlen < CPU_CACHE_LINE_BYTES) {
+ data = cmd->data->data;
+ /*
+ * Check whether data have to be copied. Reason is either
+ * misaligned start address or misaligned length.
+ */
+ if (((uintptr_t)data % CPU_CACHE_LINE_BYTES != 0) ||
+ (xferlen % CPU_CACHE_LINE_BYTES) != 0) {
+ BSD_ASSERT(xferlen < DMA_BUF_SIZE);
if ((cmd->data->flags & MMC_DATA_READ) == 0) {
memcpy(sc->dmabuf, cmd->data->data, xferlen);
}
data = sc->dmabuf;
short_xfer = true;
- } else {
- data = cmd->data->data;
}
dctrl |= blksize << SDMMC_DCTRL_DBLOCKSIZE_Pos;
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